Ventilation unit



FIG. 1 is a perspective view of the inventive ventilation unit;

FIG. 2 is an end elevational view of the ventilation unit, the opposite end being a mirror image of that shown;

FIG. 3 is a front elevational view of the ventilation unit;

FIG. 4 is a side elevational view of the ventilation unit, the opposite side being a mirror image of that shown; and,

FIG. 5 is a back view of the ventilation unit. 

The ornamental design for a ventilation unit, as shown and described. 